The present invention relates to an openable roof apparatus comprising a movable roof structure which is constructed above a large space or equipment or establishment such as a stadium, a concert hall, an event site or the like and which can freely be moved between an open position where the space is open and a closed position where the space is closed.
An openable roof apparatus can fulfill such various demands that it is possible to obtain an open feeling of the outdoors, fresh air, and so on, and it is possible also to remove or eliminate an evil due to rainy weather. These demands are contrary to each other. Many openable roof apparatuses have already been provided or proposed.
For instance, an openable roof apparatus is known which is of collapsible type comprising a roof structure. The roof structure is composed of a plurality of plane plates which are folded up and extended or expanded to move the roof structure between an object position where a space or roof building subject such as a stadium, a concert hall, an event site or the like is open and a closed positon where the space is closed.
Alternatively, as shown in FIG. 35 of the drawings attached hereto, an openable roof apparatus comprises a roof structure which is composed of a stationary roof section 1 and a movable roof section 2. The movable roof section 2 is moved to a position above or within the stationary roof section 1 to open a part of the space S.
Further, as shown in FIGS. 36 and 37, an openable roof apparatus is also known which comprises a movable roof section. The movable roof section is composed of at least two roof units 3 and 3 each of which is formed into a sectorial shape. The roof units 3 are moved angularly about a post 4 which is located at a center of the sectorial shape, whereby the movable roof section can open and close the space S. The roof units 3 jointly use the common center of angular movement. Moreover, a first support leg 5 and a second support leg 6 supporting each roof unit 3 are arranged respectively adjacent an arc of the sectorial shape forming the roof unit 3 and adjacent the center of the angular movement. The first and second legs 5 and 6 are provided respectively with slide mechanisms which are movable respectively along arcuate tracks 7 and 8.
By the way, in such conventional openable roof apparatuses, an early object can be achieved in that the roof structure can be moved between the open and closed positions. However, the conventional openable roof apparatuses have the following problems.
That is, in the openable roof apparatus of collapsible type, an accommodating section is newly required for the collapsible roof structure. Further, not only an operating mechanism becomes troublesome or cumbersome, but also a form of the roof structure is limited to a flat or plain configuration in the form of plates from the viewpoint of its construction. The openable roof apparatus lacks in its decorative design when the building is viewed as a whole.
Further, in the openable roof apparatus shown in FIG. 35, since an escaping space is required for the movable roof section 2 to be withdrawn or removed, a precise or valuable space is sacrificed. Further, since the roof arrangement becomes its form in which the movable roof section 2 is supported by the stationary roof section 1, it is required that the stationary roof section 1 is strengthened in its construction. Moreover, since the movable roof section 2 becomes also its form in which the movable roof section 2 is supported in a cantilever manner, its construction is required to be strengthened. Thus, the cost increases.
On the other hand, the openable roof apparatus shown in FIGS. 36 and 37 has such an advantage that it is possible to easily and optionally move the roof units 3 between the open and closed positions with respect to the space S. However, the following various problems to be improved arise. That is, the stability of the roof structure in the closed position, driving of the roof units 3, and so on are deteriorated so that the openable roof apparatus is not necessarily practical in use. Further, presence of the post 4 at the center of angular movement of the roof units 3 serves as a large restriction or limitation when the space S is designed above which the movable roof structure is built. Moreover, in the type in which each of the roof units 3 is supported at its center of angular movement, there are such problems that stress is concentrated with respect to the post 4 at the center of angular movement, stress is concentrated with respect to a centrl section of the roof unit 3 per se, and so on. Accordingly, it becomes difficult to design the movable roof structure at low cost from the viewpoints of its construction, at reduction in weight, and so on. Furthermore, in order to move the movable roof structure between its open and closed positions by 100%, it is required that a sidewall section of the movable roof unit 3 is also moved, simultaneously with the roof unit 3, between a closed position where the sidewall section surrounds the space S and an open position where the sidewall section is moved away from the space S. Accordingly, the cost increases.